1. Field of the Invention
The present invention relates to a method of fabricating a wire-harness and terminal connected leads composing the wire-harness which are used for an electrical cable distribution system within an automotive vehicle.
2. Description of the Prior Art
Conventionally, the connection between two wire-harnesses or between a wire-harness and another electrical device or the like is performed by engagements of the respective male and mating female connectors thereof, wherein a connector terminal used for the engagement is either of a cramping type or of a force-fitting type. A cramp-type terminal is one in which the nonconductive sheath at one end of a lead is peeled off and then the thus exposed electrically conductive portion thereof and other non-peeled still insulated external portion thereof are respectively cramped by cramping means. The cramping type terminal can not be applied to the connection of signal lines of a CPU circuit or the like, due to the fact that when even one of these signal lines is disconnected by the nonconductive sheath peeling operation, the quality of the lead as a whole can be enormously deteriorated, and that since the diameter of each signal line is so small, the size of the cramping means, or the width and height thereof after the completion of the peeling operation can not effectively be managed. On the other hand, in the case of a force-fitting type terminal, a lead as a whole is first suppressedly inserted into a slot of an electrical contact element, so that side blades of the slot cut into a part of the nonconductive sheath of the lead so as for the lead with be brought into contact to the electrical contact element, which obviates a troublesome insulating cover peeling operation, a strict size management and so on.
FIGS. 7 and 8 indicate one example of a conventional connector in which a force-fitting type terminal is adopted (Japanese Utility Model Application Laid-Open No. 59-63967). In this embodiment, a plurality of force-fitting type terminals a are individually inserted into each of accommodating paths c of a housing b and arranged therein in advance, then a lead d of the corresponding individual terminal is suppressedly inserted from the open area b1 of the housing b into a slot a2 formed in the lead connecting portion a1 of the terminal to be connected thereto. Here, since the accommodating paths c of the housing b are all in the same size, the leads d of the same size only can be suppressedly inserted and brought into contact with the terminals a of the same standards.
Generally, various kinds of terminals and leads of different electric capacity are used in wire-harnesses and terminal connecters thereof adopted for electrical cable distribution system within an automotive vehicle so as to enable the use of various vehicle-mounted type electrical devices, and therefore terminals and leads of various different standards have to be simultaneously used in one connector (housing), the combination of which can be still further variable in accordance with the types, grades of the automobile and also exporting destination thereof. The housing b disclosed in FIGS. 7 and 8 is a connector of the type that contains open portions b1 therein, so that it has to be provided with a plurality of pressing machine that can cope with, for example, various different width of terminals so as to enable the use of terminals and leads of different standards, which not only requires an increase in equipment cost and wider space, but it makes the quality management of the device as a whole substantially difficult.
In view of the foregoing situation, it is an object of the present invention to provide a method of fabricating lead connected terminals which is capable of coping with a change in the standards of the terminals and leads to be used and also provide a high reliability in the connection between these terminals and leads even if each of the leads is of a very small diameter.
In order to attain such an object as described above, the present invention provides a method of fabricating terminal connected leads for connecting a plurality of linked terminals, each of which comprises an electrically contacting portion at one end thereof, and a lead connecting portion at the other end thereof which is composed of a contact element to be brought into contact with the conductive portion of each of the leads and a crimping piece to crimp the nonconductive portion thereof to a plurality of leads by use of various devices such as; a terminal transmitter comprising a carrier strip, and the plurality of force-fitting terminals disposed at a predetermined pitch from each other and respectively connected to the carrier strip by way of respective connecting sections thereof; an intermittent terminal sending mechanism to activate the terminal transmitter for transmitting the terminals one by one; and a pressing machine provided with a force-fitting punch and a crimper, wherein the fabricating method comprising the steps of: setting the force-fitting terminals by intermittently sending each of the terminals with the intermittent terminal sending mechanism; placing one end portion of a predetermined length of each of the leads on the electrically connecting portion of the force-fitting terminal; crimping the lead by the crimping piece and pressing the lead to the contact element by lowering the force-fitting punch and the crimper respectively; and separating the thus formed force-fitting terminals from the carrier strip of the terminal transmitter by cutting the respective connecting sections of the terminals.
The above method further includes the steps of measuring and cutting a plurality of leads to form the shortened leads of a predetermined same length, and cramping and transmitting the shortened leads one by one to the pressing machine to follow.